Cartridge assembly for a track chain of a track type work machine

ABSTRACT

A cartridge assembly for a track chain assembly includes a bushing having a passageway defined therethrough. The cartridge assembly also includes track pin having a longitudinal axis. The track pin is located within the passageway so that a first end portion and a second end portion of the track pin extends outwardly from the passageway of the bushing. The cartridge assembly further includes a first insert having a first bore defined therethrough. The first insert is positioned relative to the track pin such that the first end portion of the track pin is disposed within the first bore. The cartridge assembly also includes a first collar having a first hole defined therein. The first collar is positioned relative to the track pin that (i) the first end portion of the track pin is disposed within the first hole and (ii) the first insert is interposed between the first collar and the bushing, wherein (i) the first collar is fixed in relation to the track pin such that first collar is unable to rotate relative to the track pin and (ii) the first insert is able to rotate relative to the first collar and the track pin around the longitudinal axis.

TECHNICAL FIELD

The present invention relates generally to track chains for a track typework machine, and more particularly to a cartridge assembly for a trackchain.

BACKGROUND ART

Track type work machines typically have a sprocket, an idler, and atrack chain assembly. During use of the work machine the sprocketrotates and engages the track chain assembly, thereby causing the trackchain assembly to rotate around a path defined by the sprocket and theidler. The rotation of the track chain assembly causes the work machineto be propelled over the ground so as to perform various work functions.

Track chain assemblies generally include a pair of parallel chains, witheach parallel chain being made up of a series of entrained track links.Track chain assemblies further include a series of bushings and trackpins interposed between and connected to the parallel chains. Thebushings and the entrained track links cooperate to form a number oftrack joints which allow the necessary movement of the bushings relativeto the track links during use of the track chain assembly, for example,when the track chain assembly rotates about the sprocket and the idler.

Track joints are typically equipped with a track seal assembly to keepout various corrosive and abrasive mixtures of water, dirt, sand, rockor other mineral or chemical elements to which the track chain isexposed during its use. The track seal assembly also functions to keep alubricant within the track joint to facilitate the aforementionedrelative movement of the bushings and the track links.

One prior art track seal assembly design used to accomplish theaforementioned functions employs a track link having a groove definedtherein. A sealing member is positioned within the groove and then thesealing member is axially urged into sliding sealing engagement againsta polished bushing face by a resilient rubber load ring. However, anumber of problems have been encountered using the above describedarrangement.

One such problem relates to grooving of the bushing face. The mixturesof various abrasive particles found in the working environment of atrack chain assembly tend to make excellent grinding compounds which canwear grooves into the bushing face. If these grooves become sufficientlydeep, the integrity of the track seal assembly can be compromised andabrasive particles can enter the track joint. These grooves also providea path for lubricants contained within the track joint to leak out. Allof the above discussed problems can result in the failure of the trackjoint and thus the track chain assembly. Once the track chain assemblyfails, the various parts thereof, for example the bushing and tracklink, must be replaced in a piece part manner and the track chainassembly reassembled. The process of removing the worn parts of thetrack chain assembly and then reassembling the same requires asignificant amount of time and thus decreases the productivity of thework machine.

What is needed therefore is a cartridge assembly for a track chainassembly which overcomes one or more of the above-mentioned drawbacks.

DISCLOSURE OF THE INVENTION

In accordance with one embodiment of the present invention, there isprovided a cartridge assembly for a track chain. The cartridge assemblyincludes a bushing having a passageway defined therethrough. Thecartridge assembly also includes track pin having a longitudinal axis.The track pin is located within the passageway so that a first endportion and a second end portion of the track pin extends outwardly fromthe passageway of the bushing. The cartridge assembly further includes afirst insert having a first bore defined therethrough. The first insertis positioned relative to the track pin such that the first end portionof the track pin is disposed within the first bore. The cartridgeassembly also includes a first collar having a first hole definedtherein. The first collar is positioned relative to the track pin that(i) the first end portion of the track pin is disposed within the firsthole and (ii) the first insert is interposed between the first collarand the bushing, wherein (i) the first collar is fixed in relation tothe track pin such that first collar is unable to rotate relative to thetrack pin and (ii) the first insert is able to rotate relative to thefirst collar and the track pin around the longitudinal axis.

In accordance with another embodiment of the present invention, there isprovided a cartridge assembly for a track chain. The cartridge assemblyincludes a first insert having (i) a first sidewall, (ii) a secondsidewall, (ii) a first bore defined therethrough, (iv) a first sealgroove defined in the first sidewall, and (v) a second seal groovedefined in the second sidewall. The cartridge assembly also includes atrack pin disposed within the first bore of the first insert. Thecartridge assembly further includes a bushing having a passagewaydefined therethrough. The bushing is positioned relative to the trackpin and the first insert such that (i) the track pin is disposed withinthe passageway and (ii) a first bushing end face is positioned in anopposing relationship with the first seal groove of the first insert.The cartridge assembly also includes a first collar having a first holedefined therein. The first collar is positioned relative to the trackpin and the first insert such that (i) the track pin is disposed withinthe first hole and (ii) a first collar end face is positioned in anopposing relationship with the second seal groove of the first insert.

In accordance with still another embodiment of the present invention,there is provided a cartridge assembly for a track chain. The cartridgeassembly includes an insert having (i) a first sidewall, (ii) a secondsidewall, (ii) a bore defined therethrough, (iv) a first seal groovedefined in the first sidewall, and (v) a second seal groove defined inthe second sidewall. The cartridge assembly also includes a track pindisposed within the bore of the first insert. The cartridge assemblyalso includes a bushing having a passageway defined therethrough. Thebushing is positioned relative to the track pin and the insert such that(i) the track pin is disposed within the passageway and (ii) a bushingend face is positioned in an opposing relationship with the first sealgroove of the insert. The cartridge assembly includes a collar having ahole defined therein. The collar is positioned relative to the track pinand the insert such that (i) the track pin is disposed within the holeand (ii) a collar end face of the collar is positioned in an opposingrelationship with the second seal groove of the insert. The cartridgeassembly also includes a first seal member disposed in the first sealgroove of the insert so that the first seal member contacts the bushingend face. The cartridge assembly further includes a second seal memberdisposed in the second seal groove of the insert so that the second sealmember contacts the collar end face of the collar wherein (i) the collaris fixed in relation to the track pin such that the collar is unable torotate relative to the track pin and (ii) the insert is able to rotaterelative to the collar, the track pin, and the bushing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a work machine which incorporatesthe features of the present invention therein;

FIG. 2 is a top elevational view of a segment of a track chain assemblyof the work machine of FIG. 1;

FIG. 3 is a top elevational view of a subassembly of the track chainassembly shown in FIG. 2;

FIG. 4A is a longitudinal cross sectional view of a cartridge assemblyof the track chain assembly shown in FIG. 2;

FIG. 4B is a side elevational view of the cartridge assembly shown inFIG. 4A;

FIG. 4C is an end elevational view of the cartridge assembly shown inFIG. 4B;

FIG. 5 is a perspective view of a link of the track chain assembly shownin FIG. 2;

FIG. 6 is a side elevational view of the link shown in FIG. 5;

FIG. 7 is another side elevational view of the link shown in FIG. 5;

FIG. 8 is a cross sectional view of the link shown in FIG. 5;

FIG. 9 is another cross sectional view of the link shown in FIG. 5;

FIG. 10 is another perspective view of the link shown in FIG. 5;

FIG. 11 is a cross sectional view of the track chain assembly shown inFIG. 2 taken along the line 11—11 as viewed in the direction of thearrows;

FIG. 12 is a perspective view of an off-set link which can be used inthe track chain assembly shown in FIG. 2;

FIG. 13 is another perspective view of the off-set link shown in FIG.12;

FIG. 14 is still another perspective view of the off-set link shown inFIG. 12;

FIG. 15 is a cross sectional view of an insert of the cartridge assemblyshown in FIG. 4A;

FIG. 16 is a perspective view of the insert shown in FIG. 15; and

FIG. 17 is a top elevational view of another subassembly which can beused in the track chain assembly shown in FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to FIG. 1 there is shown a work machine 10 whichincorporates the features of the present invention therein. Work machine10 includes a frame 11, an engine assembly 13, and a cab assembly 15 allmounted on frame 11. Work machine 10 also includes a work implement 17,such as a blade, mechanically coupled to frame 11. Work machine 10further includes an undercarriage assembly 12 mechanically coupled toframe 11.

Undercarriage assembly 12 includes a drive sprocket 19, a pair of idlerwheels 21 and 23, and a number of roller assemblies 25 interposedbetween idler wheels 21 and 23. (Note that the present invention canalso be utilized in oval systems.) Undercarriage assembly 12 alsoincludes a track chain assembly 14. During use of work machine 10 drivesprocket 19 rotates and engages track chain assembly 14, thereby causingtrack chain assembly 14 to rotate around a path defined by drivesprocket 19 and idler wheels 21 and 23. The rotation of track chainassembly 14 causes work machine 10 to be propelled over the ground so asto perform various work functions.

As shown more clearly in FIGS. 2 and 3, track chain assembly 14 includesa number of subassemblies 20 with track shoes 214 (see FIG. 1) attachedto each subassembly 20. As discussed in greater detail below, eachsubassembly 20 is mechanically coupled to an adjacent subassembly 20 byan outer link 18 and an outer link 18 a so that track chain assembly 14forms a closed loop. The closed loop of track chain assembly 14 isdisposed around drive sprocket 19, idler wheels 21 and 23, and rollerassemblies 25 so as to function in the above described manner.

Each subassembly 20 includes a cartridge assembly 22, a cartridgeassembly 22 a, an inner link 16, and an inner link 16 a. Cartridgeassembly 22 a is substantially identical to cartridge assembly 22,therefore only cartridge assembly 22 will be described in detail herein.

As shown in FIGS. 4A, 4B, and 4C cartridge assembly 22 includes abushing 24 having a passageway 26 defined therethrough, a track pin 28,an insert 36 having a bore 38 defined therethrough, and an insert 52having a bore 54 defined therethrough. It should be appreciated thatinsert 52 is substantially identical to insert 36, therefore only insert36 is described in detail herein. Cartridge assembly 22 also includescollar 40 having a hole 42 defined therein. Cartridge assembly 22 alsoincludes another collar 56 which is substantially identical to collar40. In particular, collar 56 also has a hole 58 defined therein.

Referring now to FIGS. 15 and 16, insert 36 includes a ring member 176having a sidewall 62 and a sidewall 64. A seal groove 50 is defined insidewall 62 such that seal groove 50 is concentric with a central axis180 of bore 38. Defining seal groove 50 in sidewall 62 results in anupper wall segment 246 and a lower wall segment 248 being formed, withseal groove 50 positioned between upper wall segment 246 and a lowerwall segment 248. Upper wall segment 246 has an inner surface 300 whichis angled away from central axis 180 such that a linear extension 250 ofa central outer surface 252 of ring member 176, which is in asubstantially parallel relationship with central axis 180, and a linearextension 254 of inner surface 300 define an angle φ therebetween.Preferably, angle φ is about 5° (note that angle φ is shown somewhatexaggerated in FIG. 15 for clarity of description).

Sidewall 64 also has a seal groove 66 defined therein which isconcentric with central axis 180 of bore 38. It should be appreciatedthat an upper wall segment 258 of ring member 176 is angled away fromcentral axis 180 in a substantially identical manner as described abovefor upper wall segment 246.

Seal groove 50 has a width W₁ and a radius R₁. It should be understoodthat what is meant herein by radius R₁ is the distance between centralaxis 180 and an inter wall segment 182 of seal groove 50 as shown inFIG. 15. Seal groove 66 also has a width W₂ and a radius R₂. In asimilar manner as that described above, what is meant herein by radiusR₂ is the distance between central axis 180 and an inner wall segment184 of seal groove 66 as shown in FIG. 15. Preferably, width W₁ issubstantially equal to width W₂. It is also preferable that radius R₁ issubstantially equal to radius R₂.

Referring back to FIG. 4A, seal groove 50 has (i) an annular thrustmember 76 and (ii) an annular seal member 72 disposed therein. Thrustmember 76 and seal member 72 are positioned in seal groove 50 so thatthrust member 76 urges seal member 72 in an axial direction as indicatedby arrow 186. It should be understood that having upper wall segment 246angled away from central axis 180 in the above described mannerfacilitates the insertion of annular thrust member 76 and annular sealmember 72 into seal groove 50 as compared to other seal groove designsthat have a straight or non-angled upper wall segment. In particular,the angling of upper wall segment 246 enhances the ability of machinerybeing utilized to insert annular thrust member 76 and annular sealmember 72 into seal groove 50. In a similar manner, seal groove 66 has(i) an annular thrust member 78 and (ii) an annular seal member 74disposed therein. Thrust member 78 and seal member 74 are positioned inseal groove 66 so that thrust member 78 urges seal member 74 in an axialdirection as indicated by arrow 188. As indicated above, having upperwall segment 258 of ring member 176 angled away from central axis 180also enhances the ability of machinery being utilized to insert annularthrust member 78 and annular seal member 74 into seal groove 66.

In a similar manner, an annular seal groove 60 of insert 52 has (i) anannular seal member 92 and (ii) an annular thrust member 190 disposedtherein. Thrust member 190 and seal member 92 are positioned in sealgroove 60 so that thrust member 190 urges seal member 92 in an axialdirection as indicated by arrow 192. An annular seal groove 84 of insert52 also has (i) an annular thrust member 194 and (ii) an annular sealmember 86 disposed therein. Thrust member 194 and seal member 86 arepositioned in seal groove 84 so that thrust member 194 urges seal member86 in an axial direction as indicated by arrow 198.

Although having both seal grooves defined in the insert is preferred, itis also contemplated that a seal groove be defined in a collar sidewall.A seal member and a thrust member is then disposed in the seal groovedefined in the collar sidewall. In this embodiment one sidewall of theinsert serves as a bearing surface for the seal member disposed in theseal groove of the collar. It is also contemplate that the thrust membercan be integral with the collar. In addition, it is contemplated thatthe thrust member can be integral with the insert.

Referring now to FIGS. 4A, 4B, and 4C, track pin 28 is inserted intopassageway 26 of bushing 24 such that bushing 24 can rotate relative totrack pin 28 in the directions indicated by arrows 200 and 204 (see FIG.4B). Insert 36 is positioned relative to track pin 28 and bushing 24such that (i) a portion 32 of track pin 28 extends through bore 38 and(ii) seal groove 50 is in an opposing relationship with an end face 68of bushing 24. Insert 36 is further positioned relative to bushing 24 sothat seal member 72 is urged against end face 68 of bushing 24 by thrustmember 76. It should be appreciated that insert 36 can rotate aroundlongitudinal axis 30 relative to both bushing 24 and track pin 28 in thedirections indicated by arrows 200 and 204 (see FIG. 4B).

Collar 40 is positioned relative to track pin 28 and insert 36 so that(i) a portion 34 of track pin 28 extends into hole 42 and (ii) an endface 70 of collar 40 is in an opposing relationship with seal groove 66.Collar 40 is further positioned relative to insert 36 so that sealmember 74 is urged against end face 70 of collar 40 by thrust member 78.Collar 40 is fixed in relation to track pin 28 so that collar 40 can not(i) rotate relative to track pin 28 or (ii) move in an axial directionrelative to track pin 28. For example, collar 40 can be laser welded totrack pin 28. Attaching collar 40 to track pin 28 in the above describedmanner enhances control over the end play of track chain 14.

Insert 52 and collar 56 are positioned relative to track pin 28 andbushing 24 in a similar manner as described above for insert 36 andcollar 40. In particular, insert 52 is positioned relative to track pin28 and bushing 24 such that (i) a portion of track pin 28 extendsthrough bore 54 and (ii) seal groove 84 is in an opposing relationshipwith an end face 88 of bushing 24. Insert 52 is further positionedrelative to bushing 24 so that seal member 86 is urged against end face88 of bushing 24 by thrust member 194. It should be appreciated thatinsert 52 can rotate relative to both bushing 24 and track pin 28 in thedirections indicated by arrows 200 and 204 (see FIG. 4B).

Collar 56 is positioned relative to track pin 28 and insert 52 so that(i) a portion of track pin 28 extends into hole 58 and (ii) an end face90 of collar 56 is in an opposing relationship with seal groove 60.Collar 56 is further positioned relative to insert 52 so that sealmember 92 is urged against end face 90 of collar 56 by thrust member190. Collar 56 is fixed in relation to track pin 28 so that collar 56can not rotate relative to track pin 28 or move in an axial directionrelative thereto. For example, collar 56 can be laser welded to trackpin 28. Attaching collar 56 to track pin 28 in the above describedmanner also enhances control over the end play of track chain 14.

As shown in FIG. 4A, track pin 28 has a lubrication reservoir 44 definedtherein. Lubrication reservoir 44 is in fluid communication with alubrication channel 46. Lubrication channel 46 leads to an outer surface48 of track pin 28. A pair of plugs 200 are located within lubricationreservoir 44 to prevent a lubricant, such as oil, from leaking out oflubrication reservoir 44. During use of cartridge assembly 22 oildisposed within lubrication reservoir 44 is advanced through lubricationchannel 46 to outer surface 48 of track pin 28. Once disposed on outersurface 48, the oil facilitates the rotation of insert 36, bushing 24,and insert 52 relative to track pin 28. The oil also lubricates sealingmembers 72, 74, 86, and 92.

Sealing members 72, 74, 86, and 92, thrust members 76, 78, 109, and 194,collar end faces 70 and 90, and bushing end faces 68 and 88 allcooperate to keep the oil within cartridge assembly 22 while keepingdebris (e.g. sand, rocks, etc) out.

Referring now to FIGS. 5-10, there is shown an inner link 16. It shouldbe understood that inner link 16 a, outer link 18, and outer link 18 aare all substantially identical to inner link 16, and thus only innerlink 16 will be described in detail herein.

Inner link 16 includes a body member 94 having (i) a side 96, (ii) aside 98, (iii) an aperture 100 defined therethrough, (iv) an aperture102 defined therethrough, (v) a rail surface 114, and (vi) a shoesurface 116. Body member 94 also has a pair of exit holes 120 and 122defined therein. However, it should be appreciated that only one exithole can be utilized in, for example, a strutless link design. Both exitholes 120 and 122 are preferably interposed between aperture 100 andaperture 102. A bolt hole 210 is positioned within each exit hole 120and 122. It should be appreciated that each bolt hole 210 is alignedwith rail surface 114 such that each bolt hole 210 is laterally centeredwith respect to the widest portion of rail surface 114. Bolt holes 210are utilized to secure a track shoe 214 to shoe surface 116 of innerlink 16. Moreover, as shown in FIG. 11, inner link 16 has a wall segment240 and a wall segment 242. Wall segment 242 is angled relative to wallsegment 240 such that a linear extension 244 of wall segment 240 andwall segment 242 define an angle σ of about 20°. Wall segment 242functions as a surface for guiding contact with roller flanges (notshown) of track chain assembly 14. Having wall segment 242 of each linkangled in the above described manner enhances the ability of the rollerflanges to guide track chain assembly 14 during use thereof.

It should be appreciated that body member 94 has a central axis 118passing therethrough so as to define a substantially 90° between (i)rail surface 114 and central axis 118 (i.e. angle α) and (ii) shoesurface 116 and central axis 118 (i.e. angle β).

Furthermore, it should be understood that body member 94 is symmetricalabout central axis 118. What is meant herein by symmetrical is theproperty of being the same or corresponding on both sides of a centraldividing line, such as central axis 118. It should further be understoodthat each half of body member 94, as defined by central axis 118, is themirror image of the corresponding half.

Inner link 16 also includes an extension member 104 extending outwardlyfrom side 96 of body member 94. Extension member 104 has a point P₁defined thereon. Inner link 16 also includes an extension member 106extending outwardly from side 96 of body member 94. Extension member 106has a point P₂ defined thereon. Inner link 16 further includes anextension member 108 extending outwardly from side 96 of body member 94.Extension member 108 has a point P₃ defined thereon.

Extension member 104, extension member 106, and extension member 108 are(i) spaced apart from each other and (ii) are preferably interposedbetween aperture 100 and aperture 102. In addition, the point P₁ definedon the extension member 104, the point P₂ defined on the extensionmember 106, and the point P₃ defined on the extension member 108 definea first plane. Moreover, side 96 of body member 94 has an outer surface110. Outer surface 110 has a point P₄ defined thereon, a point P₅defined thereon, and a point P₆ defined thereon. The point P₄, the pointP₅, and the point P₆ define a second plane which is in a substantiallyparallel relationship with the first plane. It should be appreciatedthat, preferably, (i) aperture 100 and aperture 102 are interposedbetween the point P₄ and the point P₅ and (ii) the second plane is onlytraversed by extension member 104, extension member 106, and extensionmember 108.

Side 98 of body member 94 also has an outer surface 112. Outer surface112 has a point P₇ defined thereon, a point P₈ defined thereon, and apoint P₉ defined thereon. The point P₇, the point P₈, and the point P₉define a third plane which is in a substantially parallel relationshipwith the first plane. Preferably, aperture 100 and aperture 102 areinterposed between the point P₇ and the point P₈. A pair of machiningbosses 302 are disposed on outer surface 112 so as to surround apertures100 and 102. Furthermore, it is preferable that no portion of bodymember 94 extends outwardly from side 98 so as to traverse the thirdplane other machining bosses 302.

It should be appreciated that having a link 16 in which (i) apertures100 and 102 are coplanar, (ii) each side 96 and 98 are relatively flat,and (iii) any extension members 104, 106, and 108 which extend outwardlyfrom side 96 of link 16 define a plane which is parallel with outersurface 110 is an advantage of the present invention. For example,having a link with the aforementioned characteristics results in a linkhaving planar parallel contact surfaces. Having planar parallel contactsurfaces facilitates the ability of link 16 to be appropriately locatedduring link manufacturing processes, track chain 14 assembly processes,and track chain 14 disassembly processes. In addition, having inner link16 a, outer link 18, and outer link 18 a all substantially identical toinner link 16 eliminates the need to have structurally distinct “righthand links” and “left hand links” typically used in other track chainassembly designs. Therefore, only a single type of link (i.e. link 16;links 16 a, 18, and 18 a are substantially identical to link 16 a) needsto be manufactured in order to construct track chain assembly 14,thereby simplifying and reducing the manufacturing cost of track chainassembly 14.

Furthermore, having body member 94 of link 16 symmetrical about centralaxis 118 results in an equal distribution of material at each end 206and 208 (see FIGS. 5 and 10) of link 16. Having a symmetrical link 16and an equal distribution of material at each end 206 and 208 isadvantageous. For example, it simplifies (i) design and analysistechniques, (ii) forging methods and tooling, (iii) locating andmachining methods and tooling, and (iv) heat treat equipment. Therefore,one aspect of the present invention provides a link 16 having relativelylow development and production costs.

Moreover, as shown in FIGS. 3 and 10, rail surface 114 has a width W₃,and shoe surface 116 has a width W₄ which is substantially equal towidth W₃. Having width W₃ and width W₄ substantially equal alsofacilitates locating link 16 during manufacturing, assembly, anddisassembly processes.

As previously mentioned, each subassembly 20 includes a cartridgeassembly 22, a cartridge assembly 22 a, an inner link 16, and an innerlink 16 a (see FIG. 3). Specifically, as shown in FIG. 3, inner link 16is positioned relative to cartridge assembly 22 and cartridge 22 a suchthat (i) insert 52 of cartridge assembly 22 is located within aperture100 of inner link 16, (ii) insert 52 a of cartridge assembly 22 a islocated within aperture 102 of inner link 16, and (iii) extensionmembers 104, 106, and 108 are outwardly facing in the directionindicated by arrow 224. It should be appreciated that both inserts 52and 52 a are press fit into apertures 100 and 102. Having inserts 52 and52 a press fit into apertures 100 and 102, respectively, results ininserts 52 and 52 a being unable to rotate relative to inner link 16.However, bushings 24 and 24 a, track pins 28 and 28 a, and collars 56and 56 a are able to rotate relative to inner link 16 in the directionsindicated by arrows 216, 218, 220, and 222.

In a similar manner, inner link 16 a is positioned relative to cartridgeassembly 22 and cartridge 22 a such that (i) insert 36 of cartridgeassembly 22 is located within aperture 100 a of inner link 16 a, (ii)insert 36 a of cartridge assembly 22 a is located within aperture 102 aof link 16 a, and (iii) extension members 104 a, 106 a, and 108 a areoutwardly facing in the direction indicated by arrow 226. It should beappreciated that both inserts 36 and 36 a are press fit into apertures100 a and 102 a. Having inserts 52 and 52 a press fit into apertures 100a and 102 a, respectively, results in inserts 36 and 36 a being unableto rotate relative to inner link 16 a. However, bushings 24 and 24 a,track pins 28 and 28 a, and collars 56 and 56 a are able to rotaterelative to link 16 a in the directions indicated by arrows 216, 218,220, and 222.

As shown in FIGS. 2, 3, and 11, adjacent subassemblies 20 are connectedby a pair of outer links 18 and 18 a. In particular, outer link 18 ispositioned relative to cartridge assembly 22 of subassembly 20 so that(i) collar 56 is positioned within aperture 124 of outer link 18 and(ii) extension members 104, 106, and 108 are inwardly facing in thedirection indicated by arrow 228 (see FIG. 2). In addition, outer link18 is positioned relative to inner link 16 so that a gap of about 1.5 mmis defined between outer link 18 and inner link 16. It should beappreciated that this gap is present between all adjacent inner andouter links. Outer link 18 is also positioned relative to cartridgeassembly 22 a of an adjacent subassembly 20 so that collar 56 a ofcartridge assembly 22 a is positioned within aperture 126 of outer link18 (see FIG. 2). It should be appreciated that both collars 56 and 56 aare press fit into apertures 124 and 126. Having collars 56 and 56 apress fit into apertures 124 and 126, respectively, results in collars56 and 56 a and track pins 28 and 28 a being unable to rotate relativeto outer link 18. However, bushings 24 and 24 a and inserts 52 and 52 aare able to rotate relative to outer link 18.

Outer link 18 a is positioned relative to cartridge assembly 22 ofsubassembly 20 so that (i) collar 40 is positioned within aperture 124 aof outer link 18 a and (ii) extension members 104 a, 106 a, and 108 aare inwardly facing in the direction indicated by arrow 230 (see FIG.2). Outer link 18 a is also positioned relative to cartridge assembly 22a of the aforementioned adjacent subassembly 20 so that collar 40 a ofcartridge assembly 22 a is positioned within aperture 126 a of outerlink 18 a (see FIG. 2). It should be appreciated that both collars 40and 40 a are press fit into apertures 124 a and 126 a. Having collars 40and 40 a press fit into apertures 124 a and 126 a, respectively, resultsin collars 40 and 40 a and track pins 28 and 28 a being unable to rotaterelative to outer link 18. However, bushings 24 and 24 a and inserts 36and 36 a are able to rotate relative to outer link 18 a.

Additional subassemblies 20 are coupled utilizing outer links 18 and 18a in the above described manner until a track chain assembly 14 havingan appropriate length is obtained. Preferably, track chain assembly 14is made up of an even number of links. When track chain assembly 14 ismade up of an even number of links only links 16, 16 a, 18, and 18 a arerequired to construct track chain 14. However, certain situationsrequire that track chain 14 be made up of an odd number of links. Asshown in FIG. 17, when track chain assembly 14 is made up of an oddnumber of links track chain assembly 14 must include a singlesubassembly 170 which is constructed utilizing links 128 and 128 a. Itshould be appreciated that link 128 a is substantially identical to link128 and therefore only link 128 will be described in detail herein.

As shown in FIG. 14, link 128 includes a body member 130 having (i) aside 132, (ii) a side 134, (iii) an aperture 136 defined therethrough,and (iv) an aperture 138 defined therethrough. Side 132 of body member130 has an upper edge 162 and a lower edge 164. In addition, side 134 ofbody member 130 has an upper edge 166 and a lower edge 168 (see FIG.13). Link 128 further includes an exit hole 154 and an exit hole 156defined therein. However, it should be appreciated that only one exithole can be utilized in, for example, a strutless link design. Exitholes 154 and 156 are interposed between aperture 136 and aperture 138.Link 128 also includes a bolt hole 158 and a bolt hole 160 defined inbody member 130. Bolt holes 158 and 160 are positioned within exit hole154 and exit hole 156, respectively. Link 128 also includes an extensionmember 140 extending outwardly from upper edge 162 of side 132 of bodymember 130. Link 128 also includes an extension member 142 extendingoutwardly from lower edge 164 of side 132 of body member 130. Extensionmember 142 is spaced apart from extension member 140. Link 128 alsoincludes an extension member 144 extending outwardly from upper edge 166of side 134 of body member 130. Link 128 further includes an extensionmember 146 extending outwardly from lower edge 168 of side 134 of bodymember 130. Extension member 142 is spaced apart from extension member144. Body member 130 has a rail surface 148 and a shoe surface 150. Acentral axis 152 (see FIGS. 12 and 13) passes through rail surface 148and shoe surface 150 so as to define a substantially 90° angle (i.e.angle θ) between (i) rail surface 148 and central axis 152 and (ii) a90° angle (i.e. angle φ) between shoe surface 150 and central axis 152.Body member 130 is symmetrical about central axis 152. In particular,body member 130 is symmetrical but rotated relative to body member 94.

Side 132 is off-set from side 134 so that side 132 is not coplanar withside 134. Having sides 132 and 134 off-set gives clearance betweenadjacent links 128 when utilized in track chain 14. In addition,aperture 136 is off-set from aperture 138 so that aperture 136 is notcoplanar with aperture 138. Extension member 142 and extension member146 are interposed between aperture 136 and aperture 138.

Subassembly 170 includes a cartridge assembly 22, a cartridge assembly22 a, a link 128, and a link 128 a as shown in FIG. 17. Note thatcartridge assemblies 22 and 22 a are identical to cartridge assemblies22 and 22 a discussed above in reference to FIG. 3. Link 128 ispositioned relative to cartridge assemblies 22 and 22 a such that (i)collar 40 a of cartridge assembly 22 a is located in aperture 138 and(ii) insert 36 is located in aperture 136. It should be appreciated thatcollar 40 a and insert 36 are press fit into apertures 138 and 136,respectively. In a similar manner, link 128 a is positioned relative tocartridge assemblies 22 and 22 a such that (i) collar 56 a of cartridgeassembly 22 a is located in aperture 138 a and (ii) insert 52 is locatedin aperture 136 a. It should be appreciated that collar 56 a and insert52 are press fit into apertures 138 a and 136 a, respectively.

Subassembly 170 is incorporated into track chain assembly 14 in thefollowing manner. An inner link 16 a is positioned relative to cartridgeassembly 22 a and the next adjacent cartridge assembly 22 (not shown inFIG. 17) such that (i) insert 36 a of cartridge assembly 22 a is pressfit within aperture 102 a and (ii) an insert 36 of the next adjacentcartridge assembly 22 is press fit into aperture 100 a (not shown inFIG. 17). An inner link 16 is positioned relative to cartridge assembly22 a and the next adjacent cartridge assembly 22 such that (i) insert 52a of cartridge assembly 22 a is press fit within aperture 102 a and (ii)insert 36 of the next adjacent cartridge assembly 22 is press fit intoaperture 10 a (not shown in FIG. 17). An outer link 18 a is positionedrelative to cartridge 22 and the next adjacent cartridge assembly 22 a(not shown in FIG. 17) such that (i) collar 40 of cartridge assembly 22is press fit into aperture 124 a and (ii) collar 40 a of the nextadjacent cartridge assembly 22 a is press fit into aperture 126 a (notshown in FIG. 17). An outer link 18 is positioned relative to cartridge22 and the next adjacent cartridge assembly 22 a (not shown in FIG. 17)such that (i) collar 56 of cartridge assembly 22 is press fit intoaperture 124 and (ii) collar 56 a of the next adjacent cartridgeassembly 22 a is press fit into aperture 126 a (not shown in FIG. 17).

INDUSTRIAL APPLICABILITY

Track chain assembly 14 has many advantages in addition to theadvantages already discussed in reference to the links utilized therein.For example, cartridge assembly 22 enhances track chain assembly 14 lifeby improving the retention of the lubricant within cartridge assembly22. (It should be understood that any advantage discussed in referenceto cartridge assembly 22 also applies to cartridge assembly 22 a.)Furthermore, since cartridge assembly 22 is a self-contained componentand collars 40 and 56 are permanently attached to track pin 28 (e.g. bylaser welding) cartridge assembly 22 provides a greater amount ofcontrol over axial end play as compared to track chain designs thatutilize a link press fit directly onto a track pin. Moreover, sincecartridge assembly 22 is self-contained and provides essentially all ofthe sealing and bearing functions required by track chain assembly 14,track chain assembly 14 can be easily serviced by removing old worncartridge assemblies 22 and replacing them with new cartridge assemblies22. Removing and replacing the entire cartridge assembly 22 to servicetrack chain assembly 14 is more cost effective and efficient as comparedto other track chain assembly designs which require servicing in a piecepart manner.

The inserts utilized in cartridge assembly 22 also so have severaladvantages. (Note that the following advantages apply to all of theinserts utilized in cartridge assembly 22, however, only insert 36 willbe discussed.) For example, the one piece structure of insert 36 allowstrack chain assembly 14 to be constructed without thrust washers andseal mounting shrouds which decreases the mechanical complexity and costof track chain assembly 14. Furthermore, the structure of insert 36provides for seal mounting of both seal members 72 and 74 in a singlepreassembled unit. In addition, the geometry of insert 36 allows for therelatively simple manufacturing of a straight bore 38. The straight boreof insert 36 facilitates the deflection or deformation of insert 36 uponbeing press fit into an aperture of a link (e.g. inner link 16). Thisdeformation or deflection results in insert 36 providing a good bearingcontact profile with track pin 28.

Other aspects, objects and advantages of this invention can be obtainedfrom a study of the drawings, disclosures, and the appended claims.

What is claimed is:
 1. A cartridge assembly for a track chain,comprising: a bushing having a passageway defined therethrough; trackpin having a longitudinal axis, said track pin being located within saidpassageway so that a first end portion and a second end portion of saidtrack pin extends outwardly from said passageway of said bushing, saidtrack pin has a lubrication reservoir and lubrication channel definedtherein, said lubrication channel being in fluid communication with saidlubrication reservoir and an outer surface of said track pin; a firstinsert having a first bore defined therethrough, said first insert beingpositioned relative to said track pin such that said first end portionof said track pin is disposed within said first bore said first inserthas a first annular seal groove defined therein such that said firstannular seal groove surrounds said track pin; and a first collar havinga first hole defined therein, said first collar being positionedrelative to said track pin so that (i) said first end portion of saidtrack pin is disposed within said first hole and (ii) said first insertis interposed between said first collar and said bushing, wherein (i)said first collar is fixed in relation to said track pin such that firstcollar is unable to rotate relative to said track pin and (ii) saidfirst insert is able to rotate relative to said first collar, saidbushing and said track pin around said longitudinal axis.
 2. Thecartridge assembly of claim 1, further comprising: a second inserthaving a second bore defined therethrough, said second insert beingpositioned relative to said track pin such that (i) said second endportion of said track pin is disposed within said second bore and (ii)said bushing is interposed between said first insert and said secondinsert; and a second collar having a second hole defined therein, saidsecond collar being positioned relative to said track pin that (i) saidsecond end portion of said track pin is disposed within said second holeand (ii) said first insert, said bushing, and said second insert areinterposed between said first collar and said second collar.
 3. Thecartridge assembly of claim 2, wherein: said second collar is fixed inrelation to said track pin such that said second collar is unable torotate relative to said track pin, and said second insert is able torotate relative to said first collar, said second collar, and said trackpin around said longitudinal axis.
 4. The cartridge assembly of claim 3,wherein: said second insert has a second annular seal groove definedtherein such that said second seal groove surrounds said track pin.
 5. Acartridge assembly for a track chain, comprising: a first insert having(i) a first sidewall, (ii) a second sidewall, (ii) a first bore definedtherethrough, (iv) a first seal groove defined in said first sidewall,and (v) a second seal groove defined in said second sidewall; a trackpin disposed within said first bore of said first insert; a bushinghaving a passageway defined therethrough, said bushing being positionedrelative to said track pin and said first insert such that (i) saidtrack pin is disposed within said passageway and (ii) a first bushingend face is positioned in an opposing relationship with said first sealgroove of said first insert; and a first collar having a first holedefined therein, said first collar being positioned relative to saidtrack pin and said first insert such that (i) said track pin is disposedwithin said first hole and (ii) a first collar end face is positioned inan opposing relationship with said second seal groove of said firstinsert.
 6. The cartridge assembly of claim 5, further comprising: afirst seal member disposed in said first seal groove of said firstinsert so that said first seal member contacts said first bushing endface; and a second seal member disposed in said second seal groove ofsaid first insert so that said second seal member contacts said firstcollar end face.
 7. The cartridge assembly of claim 6, furthercomprising: a first thrust member disposed in said first seal groove ofsaid first insert so that said first thrust member urges said first sealmember against said first bushing end face; and a second thrust memberdisposed in said second seal groove of said first insert so that saidsecond thrust member urges said second seal member against said firstcollar end face.
 8. The cartridge assembly of claim 5, wherein: saidfirst collar is fixed in relation to said track pin such that said firstcollar is unable to rotate relative to said track pin, and said firstinsert is able to rotate relative to said first collar and said trackpin.
 9. The cartridge assembly of claim 8, wherein: said first insert isable to rotate relative to said bushing.
 10. The cartridge assembly ofclaim 5, wherein: said track pin has a lubrication reservoir definedtherein.
 11. The cartridge assembly of claim 5, further comprising: asecond insert having (i) a third sidewall, (ii) a fourth sidewall, (ii)a second bore defined therethrough, (iv) a third seal groove defined insaid third sidewall, and (v) a fourth seal groove defined in said fourthsidewall, said second insert being positioned relative to said track pinand said bushing such that (i) said track pin is disposed in said secondbore and (ii) a second bushing end face is positioned in an opposingrelationship with said third seal groove of said second insert; and asecond collar having a second hole defined therein, said second collarbeing positioned relative to said track pin and said second insert suchthat (i) said track pin is disposed within said second hole and (ii) asecond collar end face is positioned in an opposing relationship withsaid fourth seal groove of said second insert.
 12. The cartridgeassembly of claim 11, further comprising: a third seal member disposedin said third seal groove of said second insert so that said third sealmember contacts said second bushing end face; and a fourth seal memberdisposed in said fourth seal groove of said second insert so that saidfourth seal member contacts said second collar end face.
 13. Thecartridge assembly of claim 11, wherein: said second collar is fixed inrelation to said track pin such that second collar is unable to rotaterelative to said track pin, and said second insert is able to rotaterelative to said second collar and said track pin.
 14. The cartridgeassembly of claim 13, wherein: said second insert is able to rotaterelative to said bushing.
 15. A cartridge assembly for a track chain,comprising: an insert having (i) a first sidewall, (ii) a secondsidewall, (ii) a bore defined therethrough, (iv) a first seal groovedefined in said first sidewall, and (v) a second seal groove defined insaid second sidewall; a track pin disposed within said bore of saidfirst insert; a bushing having a passageway defined therethrough, saidbushing being positioned relative to said track pin and said insert suchthat (i) said track pin is disposed within said passageway and (ii) abushing end face is positioned in an opposing relationship with saidfirst seal groove of said insert; a collar having a hole definedtherein, said collar being positioned relative to said track pin andsaid insert such that (i) said track pin is disposed within said holeand (ii) a collar end face of said collar is positioned in an opposingrelationship with said second seal groove of said insert; a first sealmember disposed in said first seal groove of said insert so that saidfirst seal member contacts said bushing end face; and a second sealmember disposed in said second seal groove of said insert so that saidsecond seal member contacts said collar end face of said collar, wherein(i) said collar is fixed in relation to said track pin such that saidcollar is unable to rotate relative to said track pin and (ii) saidinsert is able to rotate relative to said collar, said track pin, andsaid bushing.